Radiator Systems

ABSTRACT

A system of spacecraft radiators comprising pre-formed thermal-transfer modules joined together by at least one solid-state welding process. Critical failure points are eliminated by forming the thermal-transfer modules as a single unitary piece, preferably by an extrusion process. The thermal-transfer modules allow the formation of larger radiator assemblies, which may comprise a wide range of sizes and physical geometries.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is related to and claims priority from priorprovisional application Ser. No. 61/334,733, filed May 14, 2010,entitled “NOVEL METHOD OF MANUFACTURING OF RADIATOR SYSTEMS”; and, thisapplication is related to and claims priority from prior provisionalapplication Ser. No. 61/423,927, filed Dec. 16, 2010, entitled “NOVELMETHOD OF MANUFACTURING OF RADIATOR SYSTEMS”, the contents of both ofwhich are incorporated herein by this reference and are not admitted tobe prior art with respect to the present invention by the mention inthis cross-reference section.

BACKGROUND

This invention relates to improved radiator systems and novel methods ofmanufacturing such apparatus. More particularly, this invention relatesto radiator assemblies utilizing extrusion-formed modules that may becombined.

Thermal control is an important aspect of spacecraft design andoperation. A principal objective of a spacecraft thermal-controlsubsystem is to maintain internal and external components withintemperature ranges appropriate to their operation. Thermal control inspacecraft generally involves the collection, transfer, and rejection ofwaste heat from the onboard heat loads to the surrounding spaceenvironment. In the vacuum environment of space, the primary heatrejection mechanism is radiation.

Radiators and similar heat-rejection devices generally operate bytransferring heat from a fluid to a surface for radiation away from thefluid. In conventional spacecraft designs, a thermal-control subsystemmay transfer waste heat to external radiator surfaces where the heat isradiated to the surrounding space environment.

Operational safety and reliability are of prime importance in mostspacecraft apparatus due to the often critical functions they support.Radiators operated in a space environment are often subjected to extremethermal cycling, which poses heavy structural demands on the radiatorsubcomponents including the bonds formed between fluid tubes andthermal-surface components. In addition, it is important that radiatorsand similar heat-rejection devices address other risk factors includingdamage by micrometeoroid and orbital debris (MMOD) impacts.

OBJECTS AND FEATURES OF THE INVENTION

A primary object and feature of the present invention is to provide asystem overcoming the above-mentioned problems.

It is a further object and feature of the present invention to providesuch a system including methods for manufacturing radiators by joiningpre-formed thermal-transfer modules using at least one solid-statewelding process. It is another object and feature of the presentinvention to provide embodiments of such system that eliminate criticalfailure points by forming the modules as a single unitary piece,preferably by an extrusion-forming process. It is another object andfeature of the present invention to configure such thermal-transfermodules to allow the formation of larger heat-rejection assemblies,preferably including radiators and heat exchangers, preferablycomprising an extensive range of sizes and physical geometries, withscalable heat-rejection capacities ranging between several hundred wattsto several megawatts.

It is a further object and feature of the present invention to providethermal-transfer modules capable of reducing the potential for criticaldamage due to micrometeoroid and orbital debris (MMOD) impacts. Afurther primary object and feature of the present invention is toprovide such a system that is efficient, cost-effective, and useful.Other objects and features of this invention will become apparent withreference to the following descriptions.

SUMMARY OF THE INVENTION

In accordance with a preferred embodiment hereof, this inventionprovides a system, relating to heat transfer between at least one heatload and at least one surrounding environment using at least oneheat-transfer fluid, such system comprising: a thermal-transfer modulestructured and arranged to assist thermal transfer between the at leastone heat-transfer fluid and the at least one surrounding environment;wherein such thermal-transfer module comprises at least onethermal-interaction facesheet comprising a sheet-surface area structuredand arranged to thermally interact with the at least one surroundingenvironment, in thermal interaction with such at least onethermal-interaction sheet, at least one fluid channel structured andarranged to channel the at least one heat-transfer fluid within suchthermal-transfer module, and at least one modular engager structured andarranged to assisting modular engagement of such thermal-transfer modulewith at least one other such thermal-transfer module; wherein such atleast one modular engager comprises at least one solid-state-weldingfacilitator structured and arranged to facilitate fixedly joining suchat least one modular engager to at least one other such modular engagerby at least one solid-state welding process; wherein such at least onesolid-state-welding facilitator comprises at least one continuous edgestructured and arranged to assist formation with at least one other suchat least one continuous edge, a continuously weldable joint, and amaterial thickness less than or equal to about 0.1 inch (2.5millimeters); and wherein such thermal-transfer module comprises asingle extruded piece.

Moreover, it provides such a system wherein such thermal-transfer modulefurther comprises: a longitudinal axis; and transverse to and extendingcontinuously along such longitudinal axis, a fixed cross-sectionalprofile; wherein such at least one fluid channel and such at least onecontinuous edge are in parallel orientation with such longitudinal axis.Additionally, it provides such a system wherein such inner channelsurface comprises an inner channel surface area equal to or less thanone half such sheet-surface area of such at least onethermal-interaction sheet. Also, it provides such a system wherein suchthermal-transfer module comprises exactly one such at least onethermal-interaction facesheet and exactly one such at least one fluidchannel. In addition, it provides such a system wherein suchthermal-transfer module comprises at least one metallic material. And,it provides such a system wherein such at least one metallic materialcomprises substantially aluminum.

Further, it provides such a system comprising: at least one radiatorassembly structured and arranged to provide expanded heat-transfercapacity between the at least one heat load and the at least onesurrounding environment; wherein such at least one radiator assemblycomprises a plurality of such thermal-transfer modules; and at least onefriction-stir weld structured and arranged to fixedly join suchthermal-transfer modules of such plurality. Even further, it providessuch a system wherein such at least one friction-stir weld is structuredand arranged to continuously join two adjacent such at least onecontinuous edges of at least two such thermal-transfer modules.Moreover, it provides such a system wherein such at least onethermal-interaction facesheet further comprises: at least two such atleast one continuous edges; and a geometric reference plane at leastcontaining both such at least one edges. Additionally, it provides sucha system wherein such at least one thermal-interaction facesheet furthercomprises: an outer surface comprising such sheet-surface area; whereinsuch outer surface is parallel with such geometric reference plane.

Also, it provides such a system wherein: such at least onethermal-interaction facesheet further comprises an outer surfacecomprising such sheet-surface area; and such outer surface non-planar.In addition, it provides such a system wherein such outer surfacecomprises at least one curve. And, it provides such a system whereinsuch at least one curve comprises a fixed radius. Further, it providessuch a system wherein such at least one fluid channel of suchthermal-transfer module is located about equidistant of both such atleast one edges. Even further, it provides such a system wherein such atleast one radiator assembly comprises a substantially parallelarrangement of respective such geometric reference planes of suchplurality of such thermal-transfer modules.

Moreover, it provides such a system wherein such at least one radiatorassembly comprises at least one non-parallel arrangement of suchgeometric reference planes of such plurality of such thermal-transfermodules. Additionally, it provides such a system wherein such pluralityof such thermal-transfer modules of such at least one radiator assemblyare arranged to comprise a continuous perimeter.

Also, it provides such a system further comprising: at least onesheet-area modifier structured and arranged to modify such sheet-surfacearea of such at least one thermal-interaction sheet; wherein such atleast one sheet-area modifier comprises at least one additionalthermal-interaction facesheet having an additional sheet-surface areastructured and arranged to provide additional thermal surfaceinteraction with the at least one surrounding environment, and at leastone additional modular engager structured and arranged to assistingmodular engagement of such at least one sheet-area modifier with such atleast one thermal-transfer module. In addition, it provides such asystem wherein such at least one radiator assembly further comprises:such at least one additional thermal-interaction facesheet fixedlyjoined to at least one such thermal-transfer module of such plurality;wherein such at least one additional thermal-interaction facesheetprovides, within such at least one radiator assembly, an increasedsheet-surface area in thermal interaction with the at least onesurrounding environment; and wherein a ratio of such channel surface andsuch sheet-surface area is modified. And, it provides such a systemfurther comprising at least one fluid coupler structured and arranged tofluid couple such at least one fluid channel to at least oneheat-transfer-fluid circuit in fluid communication with the at least oneheat load.

Further, it provides such a system further comprising at least onevehicle comprising such at least one heat-transfer-fluid circuit and theat least one heat load. Even further, it provides such a system furthercomprising: at least one impact shield to shield such at least one fluidchannel from the impact of micrometeoroid and orbital debris originatingwithin the at least one surrounding space environment; wherein such atleast one impact shield comprises a solid-material region locatedcontinuously between such at least one fluid channel and the at leastone surrounding space environment; and wherein such at least one impactshield is integrated integrally within such thermal-transfer module.Even further, it provides such a system wherein: such at least onethermal-interaction facesheet comprises a mean cross-sectional panelthickness; and such solid-material region of at least one impact shieldcomprises an minimum interstitial thickness at least about twice that ofsuch mean cross-sectional panel thickness.

In accordance with another preferred embodiment hereof, this inventionprovides a method relating to systems to transfer heat between at leastone heat load and at least one surrounding environment using at leastone heat-transfer fluid comprising the steps of: extrusion forming aplurality of thermal-transfer modules, each one comprising a singleextruded piece structured and arranged to assist thermal transferbetween the at least one heat-transfer fluid and the at least onesurrounding environment; providing within each such thermal-transfermodule at least one thermal-interaction facesheet having a sheet-surfacearea structured and arranged to thermally interact with the at least onesurrounding environment, in thermal interaction with such at least onethermal-interaction sheet, at least one fluid channel for channeling theat least one heat-transfer fluid within such thermal-transfer module,and an inner channel surface, of such at least one fluid channel,structured and arrange to be in thermal interaction with the at leastone heat-transfer fluid during such fluid channeling; providing at leastone modular spacer structured and arranged to space apart such at leasttwo such thermal-transfer modules of such plurality; providing withineach such at least one modular spacer a spacer-surface area structuredand arranged to thermally interact with the at least one surroundingenvironment, selecting a combination of such thermal-transfer modulesand such at least one modular spacers to provide a preferred ratiobetween channel surface areas and combined sheet-surface areas; formingweldable arrangement of such selected combination of suchthermal-transfer modules and such at least one modular spacers; formingat least one radiator assembly by fixedly joining such selectedcombination of such thermal-transfer modules and such at least onemodular spacers using one or more substantially continuous welds,wherein such substantially continuous weld is formed by at least onefriction-stir-weld process.

Even further, it provides such a method further comprising the step ofproviding at least one fluid coupler structured and arranged to fluidcouple such at least one fluid channel to at least oneheat-transfer-fluid circuit in fluid communication with the at least oneheat load. Even further, it provides such a method further comprisingthe step of integrating such at least one radiator assembly within atleast one vehicle comprising such at least one heat-transfer-fluidcircuit and the at least one heat load.

In accordance with another preferred embodiment hereof, this inventionprovides a system, relating to heat transfer between at least one heatload and at least one surrounding environment using at least oneheat-transfer fluid, such system comprising: a thermal-transfer modulestructured and arranged to assist thermal transfer between the at leastone heat-transfer fluid and the at least one surrounding environment;wherein such thermal-transfer module comprises a substantially planarthermal-interaction facesheet structured and arranged to thermallyinteract with the at least one surrounding environment, and in thermalinteraction with such substantially planar thermal-interaction sheet, asingle fluid channel for channeling the at least one heat-transfer fluidwithin such thermal-transfer module; wherein such substantially planarthermal-interaction facesheet comprises a set of weldable peripheraledges, structured and arranged to assist welded joining of suchthermal-transfer module to at least one other such thermal-transfermodule using at least one solid-state-welding process; wherein suchsingle fluid channel extends longitudinally from one end of suchsubstantially planar thermal-interaction facesheet to the other and isabout equidistant of each such weldable peripheral edge; and whereinsuch thermal-transfer module comprises a single extruded piece.

In accordance with another preferred embodiment hereof, this inventionprovides a system, relating to heat transfer between at least one heatload and at least one surrounding environment using at least oneheat-transfer fluid, such system comprising: a thermal-transfer assemblystructured and arranged to assist thermal transfer between the at leastone heat-transfer fluid and the at least one surrounding environment;wherein such thermal-transfer assembly comprises a plurality ofthermal-interaction facesheets comprising structured and arranged tothermally interact with the at least one surrounding environment, and inthermal interaction with such plurality of thermal-interactionfacesheets, at least one fluid channel structured and arranged tochannel the at least one heat-transfer fluid within suchthermal-transfer module; wherein such plurality of thermal-interactionfactsheets are joined by friction-stir welds; and wherein such at leastone thermal-interaction facesheet comprises at least one materialthickness less than or equal to about 0.1 inch (2.5 millimeters).

In accordance with another preferred embodiment hereof, this inventionprovides a system, relating to heat transfer between at least one heatload and at least one surrounding environment using at least oneheat-transfer fluid, such system comprising: thermal-transfer means forassisting thermal transfer between the at least one heat-transfer fluidand the at least one surrounding environment; wherein suchthermal-transfer means comprises thermal-interaction means for thermallyinteracting with the at least one surrounding environment, suchthermal-interaction means comprising a surface area, in thermalinteraction with such thermal-interaction means, fluid channel means forchanneling the at least one heat-transfer fluid within suchthermal-transfer means, and modular engager means for assisting modularengagement of such thermal-transfer means with at least one other suchthermal-transfer means, wherein such modular engager means comprisessolid-state-welding facilitator means for facilitating fixedly joiningsuch modular engager means to at least one other such modular engagermeans by at least one solid-state welding process; wherein such fluidchannel means comprises inner channel surface means for thermal surfaceinteraction with the at least one heat-transfer fluid during suchchanneling; wherein such inner channel surface means comprises a channelsurface area equal to or less than one half such surface area of suchthermal-interaction means; and wherein such thermal-transfer meanscomprises a single extruded piece.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view, illustrating the outer face of a singlethermal-transfer module, according to a preferred embodiment of thepresent invention.

FIG. 2 shows a perspective view, illustrating the inner face of thethermal-transfer module, according to the preferred embodiment of FIG.1.

FIG. 3 shows a perspective view, illustrating the inner face of aradiator assembly joining several thermal-transfer modules, according toanother preferred embodiment of the present invention.

FIG. 4 shows the sectional view 4-4 of FIG. 1 according to the preferredembodiment of FIG. 1.

FIG. 5 shows a diagrammatic representation of a solid-state welding toolused to fixedly join the thermal-transfer modules to form the radiatorassemblies of the present invention.

FIG. 6 shows an exploded perspective view of an alternative radiatorassembly, utilizing additional modular spacers to space apart severalthermal-transfer modules, according to another preferred embodiment ofthe present invention.

FIG. 7A shows the sectional view 7-7 of FIG. 6 illustrating anadditional thermal-interaction surface provided by the modular spacer ofFIG. 6.

FIG. 7B shows an end view illustrating a reinforced modular spacer,according to another preferred embodiment of the present invention.

FIG. 7C shows a partial side view schematically illustrating a preferredend termination of a preferred embodiment of radiator assembly,according to another preferred embodiment of the present invention.

FIG. 8 shows an end view of a thermal-transfer module modified tocomprise the additional thermal-interaction facesheet of FIG. 6.

FIG. 9 shows a flow diagram describing a method of selecting acombination of such thermal-transfer modules and such modular spacers toprovide a preferred ratio between channel surface areas and combinedsheet-surface areas, according to another preferred embodiment of thepresent invention.

FIG. 10 shows an end view, of a radiator assembly having an alternateassembled geometry, according to another preferred embodiment of thepresent invention.

FIG. 11 shows an end view, of a radiator assembly having an alternateassembled geometry, according to another preferred embodiment of thepresent invention.

FIG. 12 shows an end view, of a radiator assembly having anotheralternate assembled geometry, according to an additional preferredembodiment of the present invention.

FIG. 13 shows an end view, of an additional alternate thermal-transfermodule, according to another preferred embodiment of the presentinvention.

FIG. 14 shows an end view, of an alternate radiator assembly, joiningseveral of the alternate thermal-transfer modules of FIG. 14, accordingto another preferred embodiment of the present invention.

FIG. 15 shows an end view, of an alternate radiator assembly having anenclosed assembled geometry, according to another preferred embodimentof the present invention.

FIG. 16 shows a schematic diagram, illustrating heat-transfer-fluidcircuit incorporating a radiator assembly, according to anotherpreferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE BEST MODES AND PREFERRED EMBODIMENTS OF THEINVENTION

Applicant conceived the present system when faced with the need for arange of durable low-mass radiators that could withstand the dynamicloading associated with operation in a space environment. Thermalcontrol in spacecraft includes the gathering, transfer, and rejection ofwaste heat from vehicle components to the surrounding space environment.Radiators and similar heat-rejection devices operate by transferringheat from a working fluid to a surface for radiation or convection awayfrom the fluid. In general, heat-rejection apparatus in spacecraftshould comprise relatively low mass while exhibiting robust operationalreliability.

Problems arise when radiator components are formed by joining flow tubesand independently-formed thin heat-rejection sheets. For example, intesting methods of joining flow tubes to a thin aluminum facesheet,applicant identified significant problems associated with the mechanicalperformance of these connections when the composite assemblies weresubjected to the thermal and structural loading anticipated duringmission service. In response, applicant developed the present radiatorsystem 100 including preferred methods for producing lightweightradiator assemblies from pre-formed thermal-transfer modules 102specifically designed to eliminate the above-noted assembly step andassociated performance issues.

Referring to the drawings, FIG. 1 shows a perspective view illustratingthe outer face of a single thermal-transfer module 102 according to apreferred embodiment of the present invention. FIG. 2 shows a secondperspective view illustrating the inner face of the samethermal-transfer module 102, according to the preferred embodiment ofFIG. 1. FIG. 3 shows a perspective view, illustrating the inner face ofradiator assembly 104 preferably generated by joining together a seriesof thermal-transfer modules 102 using solid-state welds 106 produced bya solid-state welding process.

In specific reference to FIG. 1 and FIG. 2, each thermal-transfer module102 preferably incorporates all functional elements of the radiatorapparatus into a single unitary piece, as shown. Thus, each unitarythermal-transfer module 102 preferably comprises a thinthermal-interaction facesheet 108 and at least one fluid channel 110, asshown. It is important to note that the thermal-interaction facesheet108 and fluid channel 110 are preferably combined as integral structureswithin thermal-transfer module 102, as shown. By preferably using asingle common parent material, coefficient of thermal expansion (CTE)mismatch and strength issues are preferably eliminated.

The preferred single-piece unitary arrangement of thermal-transfermodule 102 is preferably achieved using at least one extrusion-formingprocess. In such an extrusion-forming process, a selected material 101forming transfer module 102 is pressed through an extrusion die having apredefined shaped opening matching the selected profile ofthermal-transfer module 102. Material 101 preferably emerges from theextrusion die as a single elongated piece with the same profile as thedie opening. The resulting extruded piece preferably comprises an axisof extrusion that, for clarity of description, will be identified inthermal-transfer module 102 as longitudinal axis 114. Thus, thepreferred extrusion-forming process produces a thermal-transfer module102 having a fixed cross-sectional profile 116, as best shown in FIG. 4.

FIG. 4 shows the sectional view 4-4 of FIG. 1 according to the preferredembodiment of FIG. 1. In reference to both FIG. 4 and FIG. 1, a singlefixed cross-sectional profile 116 (oriented transverse to longitudinalaxis 114) preferably extends continuously along length A ofthermal-transfer module 102. The preferred extrusion-forming process ofradiator system 100 allows the development of modules having essentiallyany selected length A. In practical terms, length A is generally limitedby the physical size requirements of a particular radiator applicationand the physical constraints of the extrusion process. This preferredproduction methodology permits a high degree of scalability andadaptability of the embodiments of radiator system 100 to differingapparatus configurations. Upon reading this specification, those withordinary skill in the art will now appreciate that, under appropriatecircumstances, considering such issues as intended use, field of use,intended markets, etc., other applications such as, for example,terrestrial (non-space) heat rejection, etc., may suffice.

In the preferred embodiment depicted in FIG. 1 and FIG. 2,thermal-transfer module 102 preferably comprises a single facesheet 108and a single fluid channel 110, as shown. Each facesheet 108 preferablycomprises two edges 118 that are preferably located on opposing sides ofthe sheet, as shown. In one preferred embodiment of the system, eachfacesheet 108 preferably comprises two linear edges 118 that arepreferably arranged in parallel orientation to longitudinal axis 114, asshown. In the preferred embodiment depicted in FIG. 1 and FIG. 2, fluidchannel 110 is preferably located within facesheet 108 preferably aboutequidistant of both edges 118 at midline 141, as shown. As shown in FIG.2 and FIG. 4, fluid channel 110 projects outwardly from interior surface122 of facesheet 108 and is preferably arranged in parallel orientationwith longitudinal axis 114.

Facesheet 108 preferably comprises an outer thermal-interaction surface112, which is preferably arranged to thermally interact with thesurrounding environment during operation. In the vacuum environment ofspace, the primary heat rejection mechanism of outer thermal-interactionsurface 112 is radiation. Outer thermal-interaction surface 112comprises a sheet-surface area 120 preferably defined by the selectedmodule length A and transverse width B (as preferably measured betweenthe opposing side edges 118).

Fluid channel 110 is preferably configured to conduct at least oneheat-transfer fluid 300 through thermal-transfer module 102 (see alsoFIG. 16). Fluid channel 110 is preferably enclosed by anintegrally-formed wall 124 that preferably extends along the full lengthA of the extruded piece. Fluid channel 110 preferably comprises acircular cross-sectional profile to maximize thermal and fluid-flowefficiency. Upon reading this specification, those skilled in the artwill now appreciate that, under appropriate circumstances, consideringsuch issues as fluid flow rates, fluid types, cost, heat transfer rates,etc., other cross-section geometries, such as, for example, rectangular,ovular, square, triangular, etc., may suffice.

The integrally-formed wall 124 preferably comprises an inner channelsurface 126, also extending along length A, which preferably defines aninner channel surface area 128 that is preferably in fluid communicationwith heat-transfer fluid 300 during operation. Preferably, inner channelsurface 126 of fluid channel 110 is thermally coupled with the externalthermal-interaction surface 112 of facesheet 108. The mechanism of heattransfer between these surfaces is primarily thermal conduction throughthe common material forming the structures.

Referring again to FIG. 4, one preferred dimensional configuration ofthermal-transfer module 102 comprises a preferred width B of about 1.5inches (about 3.8 centimeters) and a preferred facesheet thickness Cequal to or less than about 0.04 inch (about 1 millimeter). The midline141 of the module is thus located about 0.75 inch (about 1.9centimeters) from each edge 118 and preferably corresponds to the centerpoint of the circular fluid channel 110, as shown.

Fluid channel 110 comprises a preferred inner radius R1 of about 0.9inch (about 2.3 centimeters) and outer wall radius R2 of about 0.13 inch(about 3.3 millimeters). Outer wall radius R2 is preferably selected tosupport orbital arc welding of the selected fluid couplings to theterminating ends of fluid channel 110 (see also FIG. 7C). Fillet 113 ispreferably provided at the transition from interior surface 122 tointegrally-formed wall 124, as shown. To enhance the thermal flow,fillet 113 preferably comprises a fillet radius not less than about 0.03inch (about 0.8 millimeters).

In the preferred embodiments of radiator system 100, inner channelsurface area 128 is about equal to or less than about one half thesheet-surface area 120 of thermal-interaction facesheet 108. Forexample, for a module having an arbitrary length of 1 unit, a preferredinner radius R1 of about 0.9 unit and a preferred width B of about 1.5units the ratio between sheet-surface area 120 and inner channel surfacearea 128 and is about 1.5 square units to about 0.6 square units(preferably less than about 2:1). Upon reading this specification, thosewith ordinary skill in the art will now appreciate that, underappropriate circumstances, considering such issues as design preference,intended use, thermal requirements, selected materials, technologicaladvances, etc., other area relationships such as, for example, higher orlower ratios, etc., may suffice.

Fluid channel 110 is preferably spaced away from inner channel surface126 a distance D of about 0.1 inch (about 2.5 millimeters). Thispreferred arrangement establishes a thickened region of solid material136 generally located between fluid channel 110 and surrounding spaceenvironment. This solid structure preferably functions as an impactshield 138 to protect fluid channel 110 from impacts of micrometeoroidand orbital debris (MMOD), primarily by dissipating the kinetic energyassociated with such impacts.

As clearly depicted in FIG. 4, distance D preferably corresponds to thethickness of the protective region of solid material 136. Distance D ispreferably at least about twice that of the mean cross-sectional panelthickness of thermal-interaction facesheet 108, as shown. In the presentpreferred embodiment, the mean cross-sectional panel thickness ofthermal-interaction facesheet 108 approaches facesheet thickness C. Uponreading this specification, those with ordinary skill in the art willnow appreciate that, under appropriate circumstances, considering suchissues as material selection, mission profile, space environment, userpreferences, cost, weight requirements, available materials,technological advances, etc., other protective arrangements such as, forexample, the use of thin emissive protective films, “bumper” coatings,etc., may suffice.

The preferred embodiments of radiator system 100 are preferably designedto be scalable both at the module level and at the level of the radiatorassembly. Thus, it will be understood that alternate preferredimplementations of thermal-transfer module 102 are not limited to thespecific dimensions disclosed above. In that regard, alternativepreferred configurations of alternate thermal-transfer modules 102comprise alternate preferred widths B preferably ranging between about1.5 inches and about 4 inches (between about 3.8 centimeters and about10 centimeters). Alternate preferred facesheet thicknesses C preferablyrange between less than about 0.04 inch and about 0.1 inch (betweenabout 1 millimeter and about 2.5 millimeters). The midline 141 of thealternate designs are preferably located at distances ranging betweenabout 0.75 inch and about 2 inches from each respective edge 118(between about 1.9 centimeters and about 5 centimeters). Fluid channels110 may be scaled to comprise alternate preferred inner radii R1 rangingbetween about 0.06 inch and about 0.25 inch (between about 1.6millimeters and about 6.4 millimeters) and preferably comprise outerwall radii R2 ranging between about 0.1 inch to about 0.3 inch (betweenabout 2.5 millimeters and about 7.6 millimeters). It is noted that radiiR1 should be larger than about 0.12 inch (about 3 millimeters) tocontrol pressure drop within the channel.

Alternate approaches to MMOD impact mitigation allow alternate fluidchannels 110 to be spaced away from their respective inner channelsurfaces 126 distances D preferably ranging between 0.0 inch and up toabout 0.25 inch (about 6.4 millimeters) depending on the selectedapproach. Upon reading this specification, those with ordinary skill inthe art will now appreciate that, under appropriate circumstances,considering such issues as design preference, available materials,technological advances, cost, etc., other dimensional arrangements suchas, for example, thinner facesheets in response to new material advancesand welding methodologies, larger and thicker modules for terrestrialapplications where weight is not a driving design factor, etc., maysuffice.

Material selection for thermal-transfer module 102 is based on multipleperformance criteria. Such criteria preferably include compatibilitywith extrusion-forming processes, compatibility with solid-state weldingprocesses, strength to weight ratio, thermal conductivity, andcompatibility with the selected working heat-transfer fluid, amongothers. Preferred materials include metals, more preferably aluminum,more preferably 6000 series aluminum alloys as designated by the UnitedStates Aluminum Association (industry standard terminology used herein).Preferred embodiments of radiator system 100 preferably utilize aluminum6061 alloy, preferably having between about a T4 and T6 tempercondition. Upon reading this specification, those with ordinary skill inthe art will now appreciate that, under appropriate circumstances,considering such issues as design preference, user preferences, cost,structural requirements, available materials, technological advances,etc., other material selections such as, for example, alternate aluminumalloys, titanium and its alloys, magnesium alloys, stainless steel,high-temperature polymers, cermets, etc., may suffice. Furthermore, uponreading this specification, those skilled in the art will now appreciatethat, under appropriate circumstances, considering such issues as, cost,thermal performance criteria, etc., other material combinations, suchas, for example, the inclusion of additional high-emissivity coatings,low-alpha films, applied paints or resins, etc., may suffice.

Thermal-transfer module 102 preferably comprises at least one engagementstructure 130 preferably arranged to permit physical engagement of onethermal-transfer module 102 to another. In the preferred configurationof FIG. 1 and FIG. 2, both the edges 118 of facesheet 108 preferablyfunction as engagement structures 130 preferably allowing eachthermal-transfer module 102 to engage two additional thermal-transfermodules 102, as generally shown in FIG. 3 (at least embodying herein atleast one modular engager structured and arranged to assisting modularengagement of such thermal-transfer module with at least one other suchthermal-transfer module).

Referring again to FIG. 3, each edge 118 is preferably configured toassist the formation of a substantially continuous weldable joint 134with an adjacent edge 118 of a second thermal-transfer module 102. Thispreferred arrangement is preferably configured to facilitate the fixedjoining of two thermal-transfer modules 102, preferably by enabling theuse of at least one solid-state-welding process to form a continuoussolid-state-weld 106 along weldable joint 134, as shown (at leastembodying herein wherein such at least one modular engager comprises atleast one solid-state-welding facilitator structured and arranged tofacilitate fixedly joining such at least one modular engager to at leastone other such modular engager by at least one solid-state weldingprocess and further embodying herein wherein such at least onesolid-state-welding facilitator comprises at least one continuous edgestructured and arranged to assist formation with at least one other suchat least one continuous edge, a substantially continuous weldablejoint). Preferably, weldable joint 134 comprises a weldable butt joint,as shown. Preferably, the thickness of each engagement structure 130 atweldable joint 134 comprises a material thickness about equal tofacesheet thickness C and should preferably extend inwardly from edge118 (toward midline 141) not less than about 0.5 inches (1.3centimeters) to accommodate friction-stir weld fixturing. In thepreferred embodiment of FIG. 3, each edge 118 comprises a substantiallylinear geometry that is preferably configured to assist the formation ofa substantially continuous weldable joint 134 with an adjacent linearedge 118 of a second thermal-transfer module 102.

FIG. 5 shows a diagrammatic representation of solid-state welding tool140 preferably used to fixedly join thermal-transfer modules 102 to formthe preferred radiator assemblies 104 of the present invention. Indeveloping the present system, applicant determined that conventionalfusion welding techniques produced unacceptable warping of the thinfacesheet 108. Research into alternative joining methodologiesidentified one solid-state welding process as a viable alternativejoining process. More specifically, applicant conceived friction stirwelding (FSW) as a preferred means for durably joining the preferred0.04 inch aluminum facesheets 108 without warping or distortion.

In friction-stir welding (FSW), a welding tool 140 equipped with a pin142 (also referred to as a probe) is preferably rotated and slowlyplunged into weldable joint 134 formed between two thermal-interactionfacesheets 108. The facesheets are preferably clamped in one or moreclamping fixtures that prevent the abutting joint faces from movingapart during the welding process. Pressure applied by the welding tool140 generates frictional heat between the rotating welding tool 140 andthe material of the thermal-interaction sheets 108. This heat softensthe aluminum alloy 103 (selected material 101) without reaching thematerials melting point. As weld tool 140 moves along the weld line, theplasticized material intermixes and consolidates to form a solid-phasebond fixedly joining the two thermal-interaction sheets 108.

This preferred solid-state welding methodology is capable ofconsistently producing long high-quality solid-state welds 106 with verylow distortion within the thin facesheet extrusions. Applicantdetermined that, with the correct tooling and fixturing, FSW can be usedto weld the preferred 0.04 inch (1 millimeter) 6061-T6 panels togetherwith near T4 tensile strength, which is sufficient for radiatorconstruction without additional processing, depending on performancerequirements.

Applicant contracted with Manufacturing Technologies Inc (MTI) of SouthBend, Ind. to implement the final tooling and techniques required toaccomplish a satisfactory Class 1 FSW in 0.04-inch 6061 aluminum.Successful welds were achieved using a preferred welding tool 140comprising MTI part number MTI011949 and a preferred pin 142 comprisingMTI part number MTI011801. FSW process parameters consistent with thoseestablished for aluminum compositions were preferably used. Fixturing torigidly hold the facesheets during FSW was preferably employed tominimize distortion of the sheet material. Such fixturing was preferablyenabled by means of steel plates clamped atop the aluminum facesheetswhile allowing space for travel of welding tool 140.

During development, welded test panels of 0.04-inch thick (1millimeter), 6061 aluminum were produced and tested. Radiographicinspection was performed per ASTM E1742, standard practice forradiographic examination, dye penetrant inspection by ASTM E1417,standard practice for liquid penetrant testing, and eddy currentinspection. All tests showed no defects in the welds. Additional testsamples were delivered to Stork Labs of Newtown, Pa. for tensile, yieldand hardness testing. Destructive tensile and yield tests were performedper ASTM B557 and Vickers hardness per ASTM E384.

Material hardness results showed some mechanical softening withinsolid-state welds 106 relative to the parent material but in line withexpected reductions in temper for FSW processes. Tensile strengthappeared to be in the high 20 kips per square inch (kpsi) range,generally in line with expectations (25 kpsi-35 kpsi based onapproximations from hardness results). As a reference, the recognizedultimate tensile strength range of 6061-T6 is about 42 kpsi minimum(when solution heat-treated and artificially aged); TO (annealed) isabout 18 kpsi maximum; and tensile strength in the T4 condition is about30 kpsi minimum (solution heat treated and naturally aged). Testingproduced tensile strength results of about 28.7 kpsi thereby placing thetest material close to a T4 temper condition for 6061 aluminum alloy andtypical of T4 temper within 6063 aluminum alloys.

In applications requiring higher weld performance, solid-state weld 106may preferably be “cold worked” to increase tensile strength up to about20 percent. In is noted that a tensile strength increase of 5 percentwould be sufficient to achieve the equivalent of T4 conditioning.Shot-peening, roll-burnishing, and laser hardening of the weld seam arecold-working processes suitable for such optional strengthening step,with immediate roll burnishing being most preferred. It is noted thatshot-peening is less preferred in that the technique may potentiallydisrupt the exterior radiator surface, making application of low-alphafilms problematic. Upon reading this specification, those with ordinaryskill in the art will now appreciate that, under appropriatecircumstances, considering such issues as structural requirements,available materials, etc., other metallurgical treatments such as, forexample, applying a solution heat to bring the weld back to a full T6condition of the parent material, “partial” artificial aging step takingthe material to 350-dgrees Fahrenheit and holding for twelve hours toharden the material to a T4 condition, etc., may suffice.

The radiator assembly 104 of FIG. 3 preferably comprises a plurality ofthermal-transfer modules 102 that are preferably joined by theabove-described solid-state welds 106. By using the preferredpre-fabricated extrusions and by friction stir welding using only theparent material, Coefficient of Thermal Expansion (CTE) mismatch andstrength issues are preferably eliminated within the modules.

Thermal-transfer modules 102 preferably function as building blocksenabling the modular construction of diverse heat-rejection apparatus.The preferred embodiments of radiator system 100 are preferably designedto be scalable both at the module level and at the level of radiatorassembly 104. The preferred modular design of radiator assembly 104permits the scaling of radiator units to accommodate a wide range ofheat-dissipation requirements and also flexibly accommodates uniquephysical constraints imposed by differing spacecraft configurations.More specifically, differing numbers of thermal-transfer modules 102 canpreferably be combined to form unique a radiator assembly 104 designedto a specific application. This preferred feature solves manyintegration issues where the space or geometry of the target applicationis limited or otherwise constrained. Furthermore, the geometry is notlimited to only rectangular shapes, as will be further described in FIG.10 through FIG. 15.

FIG. 6 shows an exploded perspective view of alternative radiatorassembly 150, utilizing additional modular spacers 152 to space apart aplurality of thermal-transfer modules 102, according to anotherpreferred embodiment of the present invention. FIG. 7A shows thesectional view 7A-7A of FIG. 6 illustrating an additional sheet-surfacearea 121 and optional structural enhancement provided by modular spacer152 of FIG. 6.

As in the built-up modular assembly of FIG. 3, alternative radiatorassembly 150 is preferably configured to expand the capacity for heattransfer from the working fluid and heat rejection to the surroundingenvironment. By inserting modular spacers 152 between thermal-transfermodules 102, the spacing of fluid channels 110 can preferably be varied.In addition, preferred arrangements of alternate preferred embodimentsof such modular spacers 152 function to add structural strength andrigidity to the radiator assembly. This preferred feature allows theperformance characteristics of alternative radiator assembly 150 to bemodified to address specific design and performance requirements.

The use of modular spacers 152 preferably allows the ratio betweensheet-surface area 120 and inner channel surface area 128 to be modifiedby the system designer, without altering the pre-defined configurationof the base thermal-transfer modules 102.

Each modular spacer 152 (at least embodying herein at least onesheet-area modifier structured and arranged to modify such sheet-surfacearea of such at least one thermal-interaction sheet) preferablycomprises an additional thermal-interaction facesheet 156 having anadditional sheet-surface area 121 to provide supplementary thermalsurface interaction with the surrounding space environment. Each modularspacer 152 preferably comprises at least one, more preferably two,additional engagement structures 130 configured to assist the engagementof modular spacer 152 with at least one thermal-transfer module 102, asshown in FIG. 6, or alternately preferably, additional modular spacer152.

FIG. 7B shows an end view illustrating reinforced modular spacer 153,according to another preferred embodiment of the present invention. Inaddition to providing an additional thermal-interaction facesheet 156with additional sheet-surface area 121, reinforced modular spacer 153additionally provides structural reinforcement in the form of structuralsupport member 155, as shown. Structural support member 155 preferablyreinforces the relatively thin facesheet by substantially increasingmember depth perpendicular to the facesheet, as shown. This preferredarrangement increases the ability of reinforced modular spacer 153 toresist defection under various bending moments. This also assists insupporting the thermal-transfer modules 102 to which reinforced modularspacer 153 is fixedly joined.

Reinforced modular spacer 153 is preferably formed as a single piece byan extrusion process. Alternately preferably, structural support member155 comprises a separately-formed member rigidly joined to thefacesheet, preferably by welding or alternatively preferably by bonding.

FIG. 7C shows a partial side view schematically illustrating a preferredend termination 157 of a preferred embodiment of radiator assembly 104.FIG. 7C shows reinforced modular spacer 153 of FIG. 7B joined to athermal-transfer module 102 in a preferred arrangement. Upon readingthis specification, those with ordinary skill in the art will nowappreciate that, under appropriate circumstances, considering suchissues as design preference, cost, thermal requirements, etc., othersupport arrangements such as, for example, terminating a radiatorassembly at an I-beam support, coupling flow channels with a swaged-tubemanifold, etc., may suffice.

FIG. 8 shows an end view of thermal-transfer module 102 modified tocomprise the additional thermal-interaction facesheet 156 of modularspacer 152. As illustrated in FIG. 6 and FIG. 8, additional modularspacers 152 are fixedly joined to the thermal-transfer modules 102 usingsolid-state welds 106. To facilitate the formation of such solid-stateweld 106, the peripheral edge portions of modular spacer 152 comprises apreferred thickness G about equal to thickness C at the weldable edgeregion of the facesheet. Modular spacer 152 preferably comprises anyrequired width F selected by the heat-rejection system designer. In onepreferred embodiment of the system, modular spacer 152 comprises a widthF of about 3.5 inches (about 8.9 centimeters).

As illustrated in FIG. 8, the modified assembly preferably comprises anincreased width BB and an accompanying increase in sheet-surface area,preferably combining sheet-surface area 120 and the additionalsheet-surface area 121 of the additional thermal-interaction facesheet156. In this preferred arrangement, the area of outerthermal-interaction surface available to radiate heat to the surroundingenvironment is increased by the aggregate area of the applied spacers.Thus, the ratio between outer sheet-surface area and inner channelsurface areas of fluid channel 110 is preferably modified.

FIG. 9 shows a flow diagram describing method 200 of selecting acombination of thermal-transfer modules 102 and modular spacers 152 toprovide a preferred ratio between the inner channel surfaces of fluidchannel 110 and combined sheet-surface areas exposed to the externalspace environment. In that regard, method 200 preferably comprises theinitial step 202 of extrusion forming a plurality of thermal-transfermodules 102, each one comprising a single extruded piece structured andarranged to assist thermal transfer between a working heat-transferfluid and a surrounding environment. Next, as indicated in preferredstep 204, at least one modular spacer 152 is provided to space apart atleast two thermal-transfer modules 102 of such plurality. Next, asindicated in preferred step 206, a combination of thermal-transfermodules 102 and modular spacers 152 is selected by the system designerprovide a preferred ratio between inner fluid-channel surface areas andcombined sheet-surface areas. Next, a weldable arrangement of theselected combination of thermal-transfer modules 102 and modular spacers152 is formed, as indicated in preferred step 208. Next, as indicated inpreferred step 210, at least one radiator assembly 104 is formed byfixedly joining the selected combination of thermal-transfer modules 102and modular spacers 152 using one or more substantially continuouswelds, wherein the weld is preferably formed by at least onefriction-stir-weld process.

In the additional preferred step 212, at least one fluid coupler 402 isselected to operably couple fluid channel 110 to at least one pumpedfluid loop identified herein as heat-transfer-fluid circuit 404. Thisstep at least preferably includes providing technical informationsupporting the connection of radiator assembly 104 with theheat-rejection subsystem of a vehicle. This step may preferably includeproviding design and integration support fluid coupler 402, and maypreferably include supplying of hardware, such as, for example, a set ofswage couplings incorporated within at least one manifold assembly.

In the later diagram of FIG. 16, heat-transfer-fluid circuit 404 will beshown to be in fluid communication with at least one heat load 406 of(spacecraft) vehicle 400. In the present disclosure the term vehicleshall at least be defined as a craft or similar vessel, either manned orunmanned, designed to operate in a space or a terrestrial environment.In the additional preferred step 214, assistance is preferably providedto support the integration of radiator assembly 104 within at least one(spacecraft) vehicle 400 comprising such heat-transfer-fluid circuit 404and the heat load 406. This step at least preferably includes providingtechnical support relating to the integration of one or more radiatorassemblies 104 into target application.

FIG. 10 shows a partial end view of an alternate radiator assembly 220having an alternate assembled geometry, according to another preferredembodiment of the present invention. Alternate radiator assembly 220preferably comprises a plurality of thermal-transfer modules 102 thatare preferably joined by solid-state welds 106, as shown. Eachthermal-transfer modules 102 comprises a facesheet 108 containing twocontinuous edges 118. To assist in describing the preferred geometricalrelationships between modules, the orientation of each facesheet 108will be described in terms of a geometric reference plane 224 at leastcontaining both edges of a respective facesheet 108, as shown.

In thermal-transfer modules 102, thermal-interaction surface 112 ispreferably parallel with its geometric reference plane 224 (at leastembodying herein wherein such at least one thermal-interaction facesheetfurther comprises an outer surface comprising such sheet-surface area,wherein such outer surface is parallel with such geometric referenceplane). Both the radiator assembly 104 of FIG. 3 and alternativeradiator assembly 150 of FIG. 6 preferably comprise a substantiallyparallel arrangement of respective geometric reference planes 224. Thispreferred arrangement preferably produces substantially planar radiatorgeometries. More specifically, the respective geometric reference planes224 of both the radiator assembly 104 of FIG. 3 and alternative radiatorassembly 150 of FIG. 6 fall in a single common plane. This is not truefor other preferred radiator assemblies.

Referring again to FIG. 10, alternate radiator assembly 220 preferablycomprises a non-parallel arrangement of respective geometric referenceplanes 224. More specifically, respective geometric reference planes 224of alternate radiator assembly 220 are arranged so that the angle θbetween respective adjacent planes is greater than about 180 degrees.This preferred arrangement may be used produce non-planar radiatorassemblies, as shown, thus allowing for designs that approach a curvedprofile. Upon reading this specification, those with ordinary skill inthe art will now appreciate that, under appropriate circumstances,considering such issues as design preference, cost, thermalrequirements, etc., other arrangements such as, for example, the use ofadditional modular spacers, etc., may suffice.

FIG. 11 shows an end view of an alternate radiator assembly 230 havingan alternate assembled geometry, according to another preferredembodiment of the present invention. Alternate radiator assembly 230also preferably comprises a plurality of thermal-transfer modules 102that are preferably joined by solid-state welds 106, as shown. Likealternate radiator assembly 220, alternate radiator assembly 230preferably comprises a non-parallel arrangement of respective geometricreference planes 224. Preferably, respective geometric reference planes224 of alternate radiator assembly 230 are arranged so that the angle θbetween respective adjacent planes is either greater than or less thanabout 180 degrees. More specifically, respective geometric referenceplanes 224 of alternate radiator assembly 230 are preferably arranged sothat the angles θ between adjacent geometric referenced planes 224alternate between acute and obtuse angularity. This preferredarrangement may be used to produce corrugated radiator assemblies, asshown.

FIG. 12 shows an end view of a heat-rejection assembly 240 havinganother alternate assembled geometry, according to an additionalpreferred embodiment of the present invention. Heat-rejection assembly240 preferably comprise a substantially parallel arrangement ofrespective geometric reference planes 224, however, the thermal-transfermodules 102 are preferably stacked to produce a functional heatexchanger, as shown.

FIG. 13 shows an end view of an additional alternate thermal-transfermodule 260, according to another preferred embodiment of the presentinvention. FIG. 14 shows a partial end view of an alternate radiatorassembly 262, joining several alternate thermal-transfer modules 260 ofFIG. 13, according to another preferred embodiment of the presentinvention. FIG. 15 shows an end view of alternate radiator assembly 262having an enclosed assembled geometry, according to another preferredembodiment of the present invention. Alternate thermal-transfer module260 preferably comprises a single extruded piece preferably including athin thermal-interaction facesheet 268 and at least one fluid channel110, as shown. The outer surface 264 of facesheet 268 is preferablynon-planar, as shown. More preferably, the outer surface 264 offacesheet 268 comprises at least one curve. Most preferably, the outersurface 264 of the alternate facesheet 268 comprises at least one curvehaving a fixed radius R4. This preferred arrangement permits theformation of radiator apparatus have a continuous closed perimeter 266,as shown (at least embodying herein wherein such plurality of suchthermal-transfer modules of such at least one radiator assembly arearranged to comprise a continuous perimeter). This preferred geometry isuseful in producing cylindrical-shaped external radiators, which may beintegrated within the outer envelope of vehicle.

FIG. 16 shows a schematic diagram illustrating radiator assembly 104operably integrated within vehicle 400, according to a preferredembodiment of the present invention. Radiator assembly 104 is preferablyintegrated within heat-transfer-fluid circuit 404, as shown.Heat-transfer-fluid circuit 404 is preferably depicted as a pumped fluidloop 408 that circulates a heat-transfer fluid 300 between heat load 406and radiator assembly 104. If the working fluid at heat load 406 isseparated from heat-transfer fluid 300, a heat exchanger 410 (see alsoFIG. 12) is preferably included within the design, as shown. One or morefluid-circulating pumps 412 may be used to circulate heat-transfer fluid300 through radiator assembly 104. Upon reading this specification,those with ordinary skill in the art will now appreciate that, underappropriate circumstances, considering such issues as design preference,thermal requirements, mission duration, available materials,technological advances, etc., other system arrangements such as, forexample, passisve circulation systems, heat pipes, heat pumps,accummilators, sensors, controls, redundant subsystems, etc., maysuffice.

Radiator assembly 104 further comprises at least one fluid coupler 402structured and arranged to the fluid couple fluid channels 110 toheat-transfer-fluid circuit 404. In one preferred embodiment of thesystem, fluid coupler 402 comprises a terminating header or other fluidmanifold structure that preferably couples the individual fluid channels110 to the fluid transport lines of pumped fluid loop 408. In onepreferred embodiment of the system, fluid coupler 402 comprises amanifold arrangement of swaged tubes supported within a beam-likestructural end frame (see also FIG. 7C). In one preferred arrangement,two separated manifold flow tubes are preferred within fluid coupler 402to allow for two flow paths affording additional MMOD protection.

As heat-transfer fluid 300 flows through radiator assembly 104, heat isradiated into the surrounding space environment, thus reducing the heatcontent of heat-transfer fluid 300. The cooled fluid is preferablyreturned from radiator assembly 104 where it again collects waste heatfrom heat load 406. This process is repeated continuously, as required,to provide the required heat rejection Q.

In alternate embodiments of the above-described thermal-transfermodules, the fluid tubes and facesheets may comprise individualpre-formed pieces joined together by bonding, welding, or other joiningprocess, although these embodiment arrangements are less preferred thantheir extrusion-formed counterparts. In one such alternate embodiment,heat transfer tubes are preferably mounted to the facesheets usingthermally conductive epoxy, preferably an aluminum based thermallyconductive epoxy such as “Durlaco 132” (available commercially fromCotronics Corp. in Brooklyn, N.Y.). Upon reading this specification,those skilled in the art will now appreciate that, under appropriatecircumstances, considering such issues as materials, available epoxies,required thermal conductivity, etc., other methods of mounting, such as,for example, welding, brazing, bonding, etc., may suffice.

Although applicant has described applicant's preferred embodiments ofthis invention using metric standardized units, such measurements havebeen provided only for the convenience of the reader and should not beread as controlling or limiting. Instead, the reader should interpretany measurements provided in English standardized units as controlling.Any measurements provided in metric standardized units were merelyderived through strict mechanical coding, with all converted valuesrounded to one decimal place. Although applicant has describedapplicant's preferred embodiments of this invention, it will beunderstood that the broadest scope of this invention includesmodifications such as diverse shapes, sizes, and materials. Such scopeis limited only by the below claims as read in connection with the abovespecification. Further, many other advantages of applicant's inventionwill be apparent to those skilled in the art from the above descriptionsand the below claims.

1) A system, relating to heat transfer between at least one heat loadand at least one surrounding environment using at least oneheat-transfer fluid, said system comprising: a) a thermal-transfermodule structured and arranged to assist thermal transfer between the atleast one heat-transfer fluid and the at least one surroundingenvironment; b) wherein said thermal-transfer module comprises i) atleast one thermal-interaction facesheet comprising a sheet-surface areastructured and arranged to thermally interact with the at least onesurrounding environment, ii) in thermal interaction with said at leastone thermal-interaction sheet, at least one fluid channel structured andarranged to channel the at least one heat-transfer fluid within saidthermal-transfer module, and iii) at least one modular engagerstructured and arranged to assisting modular engagement of saidthermal-transfer module with at least one other said thermal-transfermodule; c) wherein said at least one modular engager comprises at leastone solid-state-welding facilitator structured and arranged tofacilitate fixedly joining said at least one modular engager to at leastone other said modular engager by at least one solid-state weldingprocess; d) wherein said at least one solid-state-welding facilitatorcomprises i) at least one continuous edge structured and arranged toassist formation of a continuously weldable joint with at least oneother said at least one continuous edge, and ii) a material thicknessless than or equal to about 0.1 inch (2.5 millimeters); and e) whereinsaid thermal-transfer module comprises a single extruded piece. 2) Thesystem according to claim 1 wherein said thermal-transfer module furthercomprises: a) a longitudinal axis; and b) transverse to and extendingcontinuously along said longitudinal axis, a fixed cross-sectionalprofile; c) wherein said at least one fluid channel and said at leastone continuous edge are in parallel orientation with said longitudinalaxis. 3) The system according to claim 1 wherein said inner channelsurface comprises an inner channel surface area equal to or less thanone half said sheet-surface area of said at least onethermal-interaction sheet. 4) The system according to claim 1 whereinsaid thermal-transfer module comprises exactly one said at least onethermal-interaction facesheet and exactly one said at least one fluidchannel. 5) The system according to claim 1 wherein saidthermal-transfer module comprises at least one metallic material. 6) Thesystem according to claim 5 wherein said at least one metallic materialcomprises substantially aluminum. 7) The system according to claim 5comprising: a) at least one radiator assembly structured and arranged toprovide expanded heat-transfer capacity between the at least one heatload and the at least one surrounding environment; b) wherein said atleast one radiator assembly comprises i) a plurality of saidthermal-transfer modules; and ii) at least one friction-stir weldstructured and arranged to fixedly join said thermal-transfer modules ofsaid plurality. 8) The system according to claim 7 wherein said at leastone friction-stir weld is structured and arranged to continuously jointwo adjacent said at least one continuous edges of at least two saidthermal-transfer modules. 9) The system according to claim 8 whereinsaid at least one thermal-interaction facesheet further comprises: a) atleast two said at least one continuous edges; and b) a geometricreference plane at least containing both said at least two continuousedges. 10) The system according to claim 9 wherein said at least onethermal-interaction facesheet further comprises: a) an outer surfacecomprising said sheet-surface area; b) wherein said outer surface isparallel with said geometric reference plane. 11) The system accordingto claim 9 wherein: a) said at least one thermal-interaction facesheetfurther comprises an outer surface comprising said sheet-surface area;and b) said outer surface is non-planar. 12) The system according toclaim 11 wherein said outer surface comprises at least one curve. 13)The system according to claim 12 wherein said at least one curvecomprises a fixed radius. 14) The system according to claim 9 whereinsaid at least one fluid channel of said thermal-transfer module islocated about equidistant of both said at least one continuous edges.15) The system according to claim 9 wherein said at least one radiatorassembly comprises a substantially parallel arrangement of respectivesaid geometric reference planes of said plurality of saidthermal-transfer modules. 16) The system according to claim 9 whereinsaid at least one radiator assembly comprises at least one non-parallelarrangement of said geometric reference planes of said plurality of saidthermal-transfer modules. 17) The system according to claim 16 whereinsaid plurality of said thermal-transfer modules of said at least oneradiator assembly are arranged to comprise a continuous perimeter. 18)The system according to claim 7 further comprising: a) at least onesheet-area modifier structured and arranged to modify said sheet-surfacearea of said at least one thermal-interaction sheet; b) wherein said atleast one sheet-area modifier comprises i) at least one additionalthermal-interaction facesheet having an additional sheet-surface areastructured and arranged to provide additional thermal surfaceinteraction with the at least one surrounding environment, and ii) atleast one additional modular engager structured and arranged toassisting modular engagement of said at least one sheet-area modifierwith said at least one thermal-transfer module. 19) The system accordingto claim 18 wherein said at least one radiator assembly furthercomprises: a) said at least one additional thermal-interaction facesheetfixedly joined to at least one said thermal-transfer module of saidplurality; b) wherein said at least one additional thermal-interactionfacesheet provides, within said at least one radiator assembly, anincreased sheet-surface area in thermal interaction with the at leastone surrounding environment; and c) wherein at least one ratio of saidchannel surface and said sheet-surface area is modified. 20) The systemaccording to claim 7 further comprising at least one fluid couplerstructured and arranged to fluid couple said at least one fluid channelto at least one heat-transfer-fluid circuit in fluid communication withthe at least one heat load. 21) The system according to claim 20 furthercomprising at least one vehicle comprising such at least oneheat-transfer-fluid circuit and the at least one heat load. 22) Thesystem according to claim 1 further comprising: a) at least one impactshield to shield said at least one fluid channel from the impact ofmicrometeoroid and orbital debris originating within the at least onesurrounding environment; b) wherein said at least one impact shieldcomprises a solid-material region located continuously between said atleast one fluid channel and the at least one surrounding environment;and c) wherein said at least one impact shield is integrated integrallywithin said thermal-transfer module. 23) The system according to claim22 wherein: a) said at least one thermal-interaction facesheet comprisesa mean cross-sectional panel thickness; and b) said solid-materialregion of at least one impact shield comprises an minimum interstitialthickness at least about twice that of said mean cross-sectional panelthickness. 24) The system according to claim 22 wherein said at leastone additional thermal-interaction facesheet of said at least onesheet-area modifier comprises at least one structural stiffener tostructurally stiffen said at least one sheet-area modifier. 25) A methodrelating to systems to transfer heat between at least one heat load andat least one surrounding environment using at least one heat-transferfluid comprising the steps of: a) extrusion forming a plurality ofthermal-transfer modules, each one comprising a single extruded piecestructured and arranged to assist thermal transfer between the at leastone heat-transfer fluid and the at least one surrounding environment; b)providing within each such thermal-transfer module i) at least onethermal-interaction facesheet having a sheet-surface area structured andarranged to thermally interact with the at least one surroundingenvironment, ii) in thermal interaction with such at least onethermal-interaction sheet, at least one fluid channel for channeling theat least one heat-transfer fluid within such thermal-transfer module,and iii) an inner channel surface, of such at least one fluid channel,structured and arrange to be in thermal interaction with the at leastone heat-transfer fluid during such fluid channeling; c) providing atleast one modular spacer structured and arranged to space apart such atleast two such thermal-transfer modules of such plurality; d) providingwithin each such at least one modular spacer a spacer-surface areastructured and arranged to thermally interact with the at least onesurrounding environment; e) selecting a combination of suchthermal-transfer modules and such at least one modular spacers toprovide a preferred ratio between channel surface areas and combinedsheet-surface areas; f) forming weldable arrangement of such selectedcombination of such thermal-transfer modules and such at least onemodular spacers; g) forming at least one radiator assembly by fixedlyjoining such selected combination of such thermal-transfer modules andsuch at least one modular spacers using one or more substantiallycontinuous welds; h) wherein such substantially continuous weld isformed by at least one friction-stir-weld process. 26) The methodaccording to claim 25 further comprising the step of providing at leastone fluid coupler structured and arranged to fluid couple such at leastone fluid channel to at least one heat-transfer-fluid circuit in fluidcommunication with the at least one heat load. 27) The method accordingto claim 26 further comprising the step of assisting integrating such atleast one radiator assembly within at least one vehicle comprising suchat least one heat-transfer-fluid circuit and the at least one heat load.28) A system, relating to heat transfer between at least one heat loadand at least one surrounding environment using at least oneheat-transfer fluid, said system comprising: a) a thermal-transfermodule structured and arranged to assist thermal transfer between the atleast one heat-transfer fluid and the at least one surroundingenvironment; b) wherein said thermal-transfer module comprises i) asubstantially planar thermal-interaction facesheet structured andarranged to thermally interact with the at least one surroundingenvironment, and ii) in thermal interaction with said substantiallyplanar thermal-interaction sheet, a single fluid channel for channelingthe at least one heat-transfer fluid within said thermal-transfermodule; c) wherein said substantially planar thermal-interactionfacesheet comprises a set of weldable peripheral edges, structured andarranged to assist welded joining of said thermal-transfer module to atleast one other said thermal-transfer module using at least onesolid-state-welding process; d) wherein said single fluid channelextends longitudinally from one end of said substantially planarthermal-interaction facesheet to the other and is about equidistant ofeach such weldable peripheral edge; and e) wherein said thermal-transfermodule comprises a single extruded piece. 29) A system, relating to heattransfer between at least one heat load and at least one surroundingenvironment using at least one heat-transfer fluid, said systemcomprising: a) a thermal-transfer assembly structured and arranged toassist thermal transfer between the at least one heat-transfer fluid andthe at least one surrounding environment; b) wherein saidthermal-transfer assembly comprises i) a plurality ofthermal-interaction facesheets comprising structured and arranged tothermally interact with the at least one surrounding environment, andii) in thermal interaction with said plurality of thermal-interactionfacesheets, at least one fluid channel structured and arranged tochannel the at least one heat-transfer fluid within saidthermal-transfer module; c) wherein said plurality ofthermal-interaction factsheets are joined by friction-stir welds; and d)wherein said at least one thermal-interaction facesheet comprises atleast one material thickness less than or equal to about 0.1 inch (2.5millimeters). 30) A system, relating to heat transfer between at leastone heat load and at least one surrounding environment using at leastone heat-transfer fluid, said system comprising: a) thermal-transfermeans for assisting thermal transfer between the at least oneheat-transfer fluid and the at least one surrounding environment; b)wherein said thermal-transfer means comprises i) thermal-interactionmeans for thermally interacting with the at least one surroundingenvironment, said thermal-interaction means comprising a surface area,ii) in thermal interaction with said thermal-interaction means, fluidchannel means for channeling the at least one heat-transfer fluid withinsaid thermal-transfer means, and iii) modular engager means forassisting modular engagement of said thermal-transfer means with atleast one other said thermal-transfer means; c) wherein said modularengager means comprises solid-state-welding facilitator means forfacilitating fixedly joining said modular engager means to at least oneother said modular engager means by at least one solid-state weldingprocess; d) wherein said fluid channel means comprises inner channelsurface means for thermal surface interaction with the at least oneheat-transfer fluid during such channeling; e) wherein said innerchannel surface means comprises a channel surface area equal to or lessthan one half said surface area of said thermal-interaction means; andf) wherein said thermal-transfer means comprises a single extrudedpiece.